Field
Aspects of the present invention generally relate to an information processing apparatus, a method for detecting a target object in an input image, and a storage medium.
Description of the Related Art
Various methods, for detecting a target object in a captured image, have been proposed. In particular, when the image includes a plurality of target objects and one target object detected by detection processing is to be presented, preferably, a candidate of a target object that has a small occluded area and thus is appropriately visible as a whole is presented.
For example, an industrial robot, used for picking objects randomly piled on a tray to achieve automation of a parts supply or an assembly step, picks up an object, and this might cause a group of other pile of objects to collapse.
When a part of the presented target object is out of the image, or inappropriate lighting causes over or under exposure on the image, a position and orientation of the target object is likely detected incorrectly in detection processing. Such a target object is unlikely to be suitable as a picking candidate.
Therefore, when an input image includes a plurality of detection target candidates in position and orientation detection processing for the piled target object in bin picking, preferably, a target object that is appropriately visible as a whole is preferentially selected.
In a method discussed in Japanese Patent Application Laid-Open No. 2004-050390, detection is performed by using entire contour information of an object to identify the position and orientation of the object. Then, a partial area of the object is further detected by using partial contour information. Thus, an object with a small occluded area is preferentially picked up.
In a method discussed in Japanese Patent No. 03654042, reliability of detected position and orientation of each part is obtained. Then, overlapping state is obtained from a positional relationship of the detected position and orientation, and parts are picked up from the one having the highest reliability and being indicated to be at the highest position by the overlapping state.
However, the methods described above have the following problems.
In the method discussed in Japanese Patent Application Laid-Open No. 2004-050390, the priority is determined based only on the occlusion in the set partial area, and this does not necessarily mean that the determination is performed based on the occlusion in the entire object. When one of the set partial areas has a strong feature and the area having a strong feature matches with the set partial area, priority might be set high regardless of whether the partial areas having a weaker feature are occluded. Furthermore, the detection processing needs to be executed for a plurality of times, and thus the calculation cost is high.
In the method discussed in Japanese Patent No. 03654042, the detected candidate objects are all projected onto three dimensional planes, and the overlapping state of the objects is determined, to select an object with a small occluded area. Thus, when some objects are not detected or incorrectly detected, the reliability of the determination on the overlapping state of the correctly detected objects becomes low.